ABSTRACT
Humans are unique among all species in their ability to adapt to a remarkable range of environments but this leads to the inevitable consequence of being exposed to many potential pathogens for which they have not developed immune protection. The increasing spectrum of human inhabitation has resulted in newly recognized infections including neurotropic pathogens (1). Each neurological infection included in the current monograph has arisen because of one of the factors associated with emerging infections in general including genetic, biological, social, political, and economic factors (Table 1) (1). For neurological infections, the impact of these variables is incalculable as recently seen with the spread of West Nile virus infection across the North American continent (2) and the recent reports of Nipah virus infections in India and Bangladesh (3). Of interest, among these neuronotropic viral infections, the effects are appreciated immediately, providing an impetus for public health intervention, if available, as evidenced by the rapid development of vaccines for West Nile Virus that appear efficacious in horses and other species (4). Conversely, viruses that are principally gliotropic including HIV usually exhibit an insidious progression and their consequences are not appreciated as promptly (5).
